LBE Unlimited Three Prong Flash Hider 5.56x45mm NATO 1/2-28 Tpi Black. 56x45mm NATO 1/2"-28 tpi Black - The Three Prong Flash Hider comes with a 5.56 crush washer and is made from 1215 steel with 1/2"x28 threads. Use a 3/4 Wrench for Installing. Specifications for LBE Unlimited ARFH3PNG Three Prong Flash Hider 5.56x45mm NATO 1/2"-28 Tpi Black: Manufacturer: LBE Unlimited Color: Black Caliber: 5.56x45mm NATO Threads per Inch: 1/2x28 LBE Unlimited ARFH3PNG Three Prong Flash Hider 5.56x45mm NATO 1/2"-28 Tpi Black